重污染企业技术创新与减污降碳耦合协调研究

在“双碳”背景下,通过测度企业技术创新与减污降碳之间的耦合协调关系,并在此基础上通过面板向量自回归模型进一步探究其耦合协调的影响因素,以厘清重污染企业协调发展的现状。实证结果表明,技术创新与减污降碳耦合协调度的变动主要取决于企业技术创新水平,2012—2021年的耦合协调度整体在勉强协调和中级协调间浮动,主要集中在初级协调阶段,其耦合协调效应良好。环境规制和数字化程度对耦合协调度的影响显著为正,能够促进耦合协调发展。     

壳聚糖对水中重金属吸附性能的研究进展

为了有效处理水中重金属污染和提高虾头虾壳中壳聚糖的利用效率,本文对提取壳聚糖的化学降解法、微生物培养法、酶解法和微波技术法进行综述,分析壳聚糖的吸附原理、最优吸附条件和壳聚糖复合材料的优点,发现化学降解法为目前普遍使用的壳聚糖提取方法,溶液的pH值、反应温度、吸附剂用量及壳聚糖复合物的种类均会影响壳聚糖对水中重金属的吸...     

核电：工业重工化发展模式下基荷低碳能源的选择

中国的低碳发展模式需要兼顾两个方面的因素,一是经济的可持续发展,一是寻求低碳能源对发展的支撑,当前在中国能够大规模建造的低碳能源,除了水电和部分新能源外,核电在低碳能源选择中扮演着重要的角色。在分析中国经济重工化演进中电力消耗、电源结构特征的基础上,建立发展中国家经济发展与电力生产碳排放的脱钩模型,提出在低碳经济发展模式下,支撑中国经济重工化发展的高电力需求与大规模低碳电源要求的悖论,分析核电的碳排放以及核电作为主要大规模低碳基荷电源的原因,并基于结合外部成本比较核电与煤电经济性。     

重型门式脚手架在现浇箱梁施工中的应用

结合浙江省杭州市留石快速路二期工程古墩路跨线桥连续现浇预应力箱粱施工实例并根据以往的施工经验,介绍在支架方案的选择上结合实际地形情况采用多种支架组合,说明了影响现浇箱梁支架施工进度、成本的几个重要因素,指出现浇箱梁支架施工采用重型门式脚手架相比其他支架施工的优点,为项目的施工进度、成本控制提供借鉴.     

我国实施现代风险导向审计存在的问题及建议

我国在实施风险导向审计中仍然存在很多问题。文章对现代风险导向审计在实际应用中存在的问题进行了分析,并提出了相应的改进建议。     

辽宁省城市工业废弃地的植物修复研究

城市工业废弃地可能已经受到原有生产活动产生的有毒有害物质的污染影响,原有生态系统遭到严重破坏.尤其是废弃矿山,土壤重金属重度污染,生态恢复极为困难.植物群落的修复成为矿区生态系统修复中最为关键性的一步.通过对植物进行野外调查,并测定矿区的优势植物对重金属的富集与转移能力,筛选出适合矿区土壤状况的重金属忍耐型植物,然后优选植被配置模式,并加强后期维护管理,完成植物修复工程.     

江苏省企业环境保护核查现状及对策

以近年来江苏省通过环保核查的拟上市及再融资的重污染企业为研究对象,分析目前环保核查中企业存在较为突出的环保问题.针对目前我国在上市公司环保核查方面存在的不足,提出进一步完善上市环保核杏建议及意见.     

Valuación de opciones de tipo de cambio asumiendo distribuciones α-estables

This paper aims to present the valuation of options using the Black-Scholes method assuming α-stable distributions as an alternative option valuation in the Mexican market. The use of α-stable distributions for modelling financial series allows to overcome the classical valuation main weakness which assumes normality, by capturing the presence of heavy tails and asymmetry in financial time series. One of the main results is the price differential between the two models and the effect of alpha and beta parameters on prices; to show the difference valuation is made of a call option and a put option for the peso-dollar exchange rate. Likewise, basic sensitivity measurements of options (delta, gamma, and rho) were made and the effect of the stability parameter (α) was made on the implied volatility of options assuming the α-stable price as the market price.     

Fourier-analytic measures for heavy-tailed insurance losses

We propose a family of three ‘Fourier-analytic’ measures to extend the conventional concepts of standard deviation, variance, and coefficient of variation to insurance losses with arbitrarily heavy tails. After motivating and computing their mathematical forms, we apply the proposed measures to the case of Lévy-stable loss portfolios. Finally, the new measures are used to study the diversification properties of heavy-tailed losses.     

Characterisation and Diagnosis of Rural—Urban Interface Farming in the Tu Liem and Thanh Tri Districts of Hanoi City,Vietnam

A research project was carried out in two areas in the outskirts of Hanoi city using a combination of qualitative and quantitative methods. The objective was to study interactions among the vegetable farming systems and the peri-urban context within which they are situated. The farms studied were characterised as small-scale farms that use high inputs of soil amendments and pesticides for diversified crop rotation systems. The main source of irrigation water and nutrients for vegetable farming in southern Hanoi is wastewater from the To Lich River. In northern Hanoi, irrigation water is obtained directly from the Red River and nutrients are supplied through high fertiliser inputs. The concentrations of COD (144–287 mg l^?1), N-NH₄ ⁺ (1–25 mg l^?1), PO₄ ^3? (0.5–4 mg l^?1) and coliform (525 × 10³?28 × 10⁶ MPN 100 ml^?1) along the To Lich River was much higher than the limits specified in the Vietnamese standard for water used in agriculture. A higher Cu content in soil in Phuc Ly seems to be linked to the high input of chicken manure at the site. However, the contents of heavy metals in irrigation water, in vegetables and in the soil surface layer at the two sites were lower than the Vietnamese maximum permissible levels.